Plug-in type christmas tree light

ABSTRACT

This invention pertains to a lamp, lamp-base and lamp-socket combination particularly adaptable for series wired Christmas tree lighting strings and of an improved plug-in type.

United States Patent Davis, Jr.

[ PLUG-IN TYPE CHRISTMAS TREE LIGHT [76] Inventor: George B. Davis, Jr., 7512 Marbury Rd., Bethesda, Md. 20014 22 Filed: Feb. 20, 1973 21 Appl. No.: 333,536

52 U.S. C1. 339/65, 339/176 L, 339/220 L, 339/221 L [51] Int. Cl. ..H0lr13/20,I-I01r9/l6 [58] Field of Search 339/65, 66 R, 66 T, 59 R,

339/59 L, 60 R, 61 R, 61L, 144 T, 176 R, 176 L, 177L, 144 R, 195 L, 191 L, 220R, 220 L, 220 T, 221 R, 221 L; 240/10 R, 10 T,

[451 Apr. 16, 1974 320,117 6/1885 Cunningham 339/191 L X 2,983,838 5/1961 Pechy 339/144 R UX 3,440,597 4/1969 Baker et a1 339/221 R FOREIGN PATENTS OR APPLICATIONS 639,028 5/1962 Italy 339/176 L Primary Examiner-Joseph I-I. McGlynn Assistant Examiner-Richard P. Tremblay 5 7 ABSTRACT This invention pertains to a lamp, lamp-base and lamp-socket combination particularly adaptable for series wired Christmas tree lighting strings and of an improved plug-in type.

4 Claims, 6 Drawing Figures 1 PLUG-IN TYPE CHRISTMAS TREE LIGHT The primary object of the present invention is to provide a lamp, base and socket combination of the simplest and most economical form of structure that upon assembly may require no soldering, yet highly reliable Other objects and advantages of the present invention will become more apparent during the course of reviewing the following description that sets forth in detail the novel structure and arrangement of parts of the device and which is shown to advantage in-the accompanying drawings wherein:

FIG. 1 is a plan view in elevation of the assembled device as would be wired within a lighting series.

FIG. 2 is a plan view in elevation, partly cut-away, of the lamp and lamp base assembly.

FIG. 3 is a plan view in elevation, partly cut-away, of the lamp and lamp base rotated 90 counterclockwise from the assembly shown in FIG. 2. 7

FIG. 4 is a base view in elevation of the assembly of FIG. 2 v

FIG. 5' is a cross-sectional view, partly in elevation, of the lamp socket assembly.

FIG. 6 is an end view in elevation of the lamp socket of FIG. Sand showing the arrangement of the lamp base receiving recess within the socket.

Referring now to the drawings and particularly to FIG. 1 thereof where is shown the lamp, lamp-base, and lamp-socket as assembled and electrically wired by electrical supply leads 5 and 6 within a series con nected string of Christmas tree lights. The lamp 7 and lamp-base 8 are shown in FIGS. 2 and 3 as a replaceable unit for being received withina suitably formed recess provided therefor within the lamp-socket member 9.

The lamp 7 is of the miniture series type and is cemented upon assembly within a suitably formed recess provided within the lamp-base member 8 with the leads l0 and 11 of the lamp extending downward through a pair of diametrically spaced passages 12 and 13 provided therefor within the lamp-base as shown. The base includes a somewhat rectangular plug type male guide portion 14 through which the lamp leads extend and which serves, as will be hereafter more fully described, to properly position the base within the socket as the lamp and base assembly is inserted therein.

The lamp leads l0 and 11, after passing through the recesses in the base, double back along the side of the base plug portion 14 after first passing through transversenotches 15 and 16 formed within the lower end of the guide 14. The purpose of these notches is to position the leads l0 and 11 inwardly from the lower end 17 of the guide and thusly prevent the leads from being rubbed, bent or tangled during rotation of the lamp and base as the latter is positioned within the socket for insertion over the terminal pins of the socket and as will become more apparent as the description proceeds.

The extending flange 19 upon the lamp base, provides means for easily lifting the lamp and base from the socket member 9 should the lamp need replacing.

FIG. 5 is a cross-sectional view, partly in elevation, of the unitary lamp socket and showing the arrangement and assembly of the terminal pins 21 and 22 therein and as connected to the power supply leads 5 and 6. During assembly these leads 5 and 6 are threaded completely through the socket by way of passages 23 and 24 and to extend well beyond the lamp base receiving cavity 25. The insulation is then stripped from the end portions of the leads after which the terminal pins 21 and 22 are sleeved over the bare wires to be crimped thereto as at 26 and 27. This crimping or pinching of the pins operates to increase their diameter at the position of the pinch and which serves, as the pins are subsequently pressed into position within the base, to lock the pins within the socket passages against rotary as well as axial movement. The pins are sufficiently long between the pinch and terminal wires as to provide a suitable guide surface for proper alignment within the socket passages before the pins are forced into their final and seating position. It is understood that the leads 5 and 6 may be soldered within the recesses provided therefor within the bases of the terminal pins 21 and 22 if so desired, however, it has been well established that crimping or pinching together electrical contacting surfaces, is often superior to solder because of the possibility of poor soldering procedures. Additionally, the pinches 26 and 27 provide the positioning means for the pins as they are forced or drawn into the socket passages.

The open end of the socket, as shown in FIG. 6, illustrates the arrangement of the pins within the female guide portion 30 of the socket and wherein-the male guide portion 14 of the lamp base is received during lamp and socket assembly. It will be noted in FIG. 5 that the extending ends of the pins are well below the shoulder 31 within the base recess thereby assuring proper alignment of the guide surfaces before the lamp base can be forced into seating and electrical contacting position over the terminal pin portions 32 and 33.

. The terminal pins portions at 32 and 33 are somewhat smaller in diameter than that portion of the pins secured within the body passages, the purpose therefor being to reduce the surface resistance and possible damage to the lamp leads as the pins are directed into the base passages already occupied by the lamp leads.

The pin portions 32 and 33 may be roughened, if so desired, as by acid etching to abrasively scrape the copper oxide from the lamp leads as the terminal pins slide along the surfaces thereof during lamp mounting, however, it has been found that even with polished terminal pins an excellent electrical connection is established between the pins and lamp leads as the lamp-base is moved into seating position within the lamp-socket. Frequently, with other similar type devices, it is necessary to scrape the copper oxide from the lamp leads before a suitable electrical connection can be made within the socket. With the present device, the somewhat resillient plastic material of the lamp-base causes the lamp leads to yieldably press against the terminal pins in a manner to almost completely remove the copper oxide from the inner face of the leads before the terminal pins have penetrated to their maximum inner position within the lamp-base.

To position the lamp leads longitudinally against one wall of the lamp-base passages, the lamp may be slightly twisted within its recess in the base before the cement 35 hardens to secure the lamp in a fixed position. To clarify, if the lead nearest the operator is doubled back upon the right side of the guide 14, a slight rotation of the lamp counterclockwise will position the lamp lead against the right wall of the passage while the other lead is positioned against the left wall of the other passage. This operation further provides for tightening the lamp leads within there respective passages and assures easier pin access to the passages upon lamp-base and lamp-socket assembly.

While here is shown and described one embodyment of the invention, it is understood that detail modifications may be resorted to without deporting from the spirit and scope of the device as shown.

What I therefore claim and desire to cover by letters patent is:

1. A lamp, lamp-base, and lamp-socket combination including a lamp having a pair of electrical leads extending from one end thereof, a non-conductive lampbase recessed for receiving the leads extending end of axially parallel passages through said socket and having axes substantially common with the passages through said lamp-base, conductive terminal pins extending from within said socket passages into the socket recess and positioned for being received with said lamp leads within the passages in said lamp-base to respectively electrically contact the leads of said lamp, said terminals pins portions within said lamp-socket passages having at least partially recessed end portions, current supply leads extending respectively into said socket passages wherein the current supply leads are secured within the recesses in said terminal pins by a portion of said pins being crimped about said leads, said crimp enlarging said pins for frictionally engaging said socket passages to assist securement of said terminal pins within said lamp socket.

2. A lamp, lamp-base and lamp-socket combination as claimed in Claim 1 wherein the terminal pins at at least one point is greater in diameter than the passages through said lamp-socket.

3. A lamp, lamp-base and lamp socket combination as claimed in Claim 1 wherein the lamp-base and lampsocket includes matching guide surfaces for aligning the terminal pins of said lamp-socket with the passages within said lamp-base before any penetration of said pin within said passages.

4. A lamp, lamp-base and lamp-socket combination as claimed in claim 1 wherein the lamp-base includes an extending flange larger in diameter than the diameter of said lamp socket and accessible for removing the lamp and lamp-base from said lamp-socket. 

1. A lamp, lamp-base, and lamp-socket combination including a lamp having a pair of electrical leads extending from one end thereof, a non-conductive lamp-base recessed for receiving the leads extending end of said lamp, a pair of substantually axially parallel passages extending from said recess through said lampbase and through which extends respectively the leads of said lamp with said leads doubling back upon the outer surface of said lamp-base, a unitary lamp-socket of non-conductive material having means forming a recess for receiving therein said lampbase, substantially axially parallel passages through said socket and having axes substantially common with the passages through said lamp-base, conductive terminal pins extending from within said socket passages into the socket recess and positioned for being received with said lamp leads within the passages in said lamp-base to respectively electrically contact the leads of said lamp, said terminals pins portions within said lamp-socket passages having at least partially recessed end portions, current supply leads extending respectively into said socket passages wherein the current supply leads are secured within the recesses in said terminal pins by a portion of said pins being crimped about said leads, said crimp enlarging said pins for frictionally engaging said socket passages to assist securement of said terminal pins within said lamp socket.
 2. A lamp, lamp-base and lamp-socket combination as claimed in Claim 1 wherein the terminal pins at at least one point is greater in diameter than the passages through said lamp-socket.
 3. A lamp, lamp-base and lamp socket combination as claimed in Claim 1 wherein the lamp-base and lamp-socket includes matching guide surfaces for aligning the terminal pins of said lamp-socket with the passages within said lamp-base before any penetration of said pin within said passages.
 4. A lamp, lamp-base and lamp-socket combination as claimed in claim 1 wherein the lamp-base includes an extending flange larger in diameter than the diameter of said lamp socket and accessible for removing the lamp and lamp-base from said lamp-socket. 